There are many industrial operations which require that a supply of liquid be spread into a continuously flowing thin sheet and deposited on a surface. Among such operations is the step of forming a sheet of pulp that eventually becomes a finished pulp or paper product. In this operation, a large drum rotates partially submerged in a pool of pulp dispersed in water. As the drum rotates, a suction is applied from inside the drum causing pulp to be deposited on the drum. The wet pulp sheet on the drum must be washed several times to remove any impurities and recover the chemicals. In so doing, it is necessary to apply to the sheet of pulp sufficient wash water to displace the chemical laden liquid within the pulp sheet. It is not feasible to apply wash water in the form of a spray because it would cause loss of washing efficiency due to air impingement causing a displacement reduction. Because of economic and environmental requirements, it is desirable to operate with a minimum displacement ratio. Accordingly, it has been found necessary to distribute the wash water in the form of a thin film that can be applied gently to the surface of the moving sheet of wet pulp. Normally, there is a spillway surface which would direct a film of water tangentially onto the moving pulp sheet and the only problem is to be able to distribute the wash water evenly over the spillway so as to produce a consistent and gently flowing sheet of wash water to the wet pulp sheet. Spoon deflectors, whistle showers, and wires have been employed in the past to change individual streams of water into spray patterns that will distribute themselves automatically over the surface of a spillway. These have been unsatisfactory for several reasons including inconsistencies in the thickness of the film of water as well as inconsistencies in the uniformity of flow across the face of the washing apparatus. Furthermore, these previously used devices caused an undesirable amount of heat loss in the wash water.
Accordingly, it is an object of this invention to provide an improved liquid distribution device which can continuously supply a sheet of wash water in a constant thickness to a spillway which directs the film of water onto a moving pulp sheet. It is another object of this invention to provide an improved distribution device that minimizes the heat loss involved in the distribution. Still another object of this invention is to provide an improved liquid distribution device which is not subject to plugging and, therefore, is less likely to produce varying thicknesses in the sheet of liquid being distributed. Still, other objects will be apparent from the more detailed description of this invention which follows.